In German utility model 203 04 453 published 24 Jul. 2003 an umbrella is described having a shaft having upper and lower ends and defining an axis, a head piece at the upper end forming a plurality of seats, and ribs fitted to the seats. A canopy fitted over the ribs outside the head piece and struts are engaged between central regions of the ribs and a slider on the shaft for opening and closing the umbrella.
When such an umbrella is exposed to excessive wind, the canopy can invert, that is move from a position where it is concave toward the lower-end handle to a position where it is oppositely concave. When this happens the ribs can pull out of the head piece, ruining the structure and basically making the umbrella unusable. Depending on the construction of the head piece, such inversion can bend the inner ends of the ribs and break or permanently damage them.